package org.apache.lucene.search.spans;
/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.util.ToStringUtils;

import java.io.IOException;
import java.util.Arrays;
import java.util.Collection;

/**
 * Only return those matches that have a specific payload at
 * the given position.
 * <p/>
 * 
 */
public class SpanNearPayloadCheckQuery extends SpanPositionCheckQuery {
    protected final Collection<byte[]> payloadToMatch;

    /**
     * @param match          The underlying {@link SpanQuery} to check
     * @param payloadToMatch The {@link java.util.Collection} of payloads to match
     */
    public SpanNearPayloadCheckQuery(SpanNearQuery match, Collection<byte[]> payloadToMatch) {
        super(match);
        this.payloadToMatch = payloadToMatch;
    }

    @Override
    protected AcceptStatus acceptPosition(Spans spans) throws IOException {
        boolean result = spans.isPayloadAvailable();
        if (result == true) {
            Collection<byte[]> candidate = spans.getPayload();
            if (candidate.size() == payloadToMatch.size()) {
                //TODO: check the byte arrays are the same
                //hmm, can't rely on order here
                int matches = 0;
                for (byte[] candBytes : candidate) {
                    //Unfortunately, we can't rely on order, so we need to compare all
                    for (byte[] payBytes : payloadToMatch) {
                        if (Arrays.equals(candBytes, payBytes) == true) {
                            matches++;
                            break;
                        }
                    }
                }
                if (matches == payloadToMatch.size()) {
                    //we've verified all the bytes
                    return AcceptStatus.YES;
                } else {
                    return AcceptStatus.NO;
                }
            } else {
                return AcceptStatus.NO;
            }
        }
        return AcceptStatus.NO;
    }

    @Override
    public String toString(String field) {
        StringBuilder buffer = new StringBuilder();
        buffer.append("spanPayCheck(");
        buffer.append(match.toString(field));
        buffer.append(", payloadRef: ");
        for (byte[] bytes : payloadToMatch) {
            ToStringUtils.byteArray(buffer, bytes);
            buffer.append(';');
        }
        buffer.append(")");
        buffer.append(ToStringUtils.boost(getBoost()));
        return buffer.toString();
    }

    @Override
    public Object clone() {
        SpanNearPayloadCheckQuery result = new SpanNearPayloadCheckQuery((SpanNearQuery) match.clone(), payloadToMatch);
        result.setBoost(getBoost());
        return result;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (!(o instanceof SpanNearPayloadCheckQuery))
            return false;

        SpanNearPayloadCheckQuery other = (SpanNearPayloadCheckQuery) o;
        return this.payloadToMatch.equals(other.payloadToMatch) && this.match.equals(other.match) && this.getBoost() == other.getBoost();
    }

    @Override
    public int hashCode() {
        int h = match.hashCode();
        h ^= (h << 8) | (h >>> 25); // reversible
        //TODO: is this right?
        h ^= payloadToMatch.hashCode();
        h ^= Float.floatToRawIntBits(getBoost());
        return h;
    }
}